Update:
I open template.php in ‘wp-admin/includes’ and goto line 195:
<td><?php if ( current_user_can( 'delete_page', $id ) ) { echo "<a href='" . wp_nonce_url( "page.php?action=delete&post=$id", 'delete-page_' . $id ) . "' class='delete' onclick=\"return deleteSomething( 'page', " . $id . ", '" . js_escape(sprintf( __("You are about to delete the '%s' page.\n'OK' to delete, 'Cancel' to stop." ), get_the_title() ) ) . "' );\">" . __( 'Delete' ) . "</a>"; } ?></td>
and remove
onclick=\"return deleteSomething( 'page', " . $id . ", '" . js_escape(sprintf( __("You are about to delete the '%s' page.\n'OK' to delete, 'Cancel' to stop." ), get_the_title() ) ) . "' );\"
from the line everything works as expected…
Is there something not being sent to WP via this javascript function?